Pneumatic dispatch system



2 Sheets-Sheet Filed Aug. 14, 1930 7 we7zZ07 June 21, 1932.

June 21, 1932. R TAlSEY 1,864,157

PNEUMATIC DISPATCH SYSTEM Filed Aug. 14, 1950 2 Sheets-Sheet 2 tion and the cessation air flow directly controlled by the carriers Patented June 21, 1932 UNITED STATES PATENT OFFICE,

FRED .R. TAISEY, F LOWELL, MASSACHUSETTS, ASSIGNOR TO THE LAMSON COMPANY,

01 SYRACUSE, NEW YORK, A CORPORATION OF MASSACHUSETTS w PNEUMATIC DISIATGH SYSTEM Application .filed August 14, '1930. Serial No. 475,167.-

Thisinvention relates to an improvement in a pneumatic dispatch system of the minimum flow vacuum type, and more particularly to the power control apparatus by I which the movement of the carrier impelling air flow is controlled.

Power control apparatus of this general type is disclosed in the patent to Libby No. 968,576, dated August 30, 1910, wherein are provided automatic pressure actuated means for initiating a carrier impelling air flow through the transmission tube whenever a carrier is entered therein, as well as means for cutting off such flow after the lapse of a predetermined period of time. WhileI regard the patented device as generally correct in principle and highly efiective in practice, I believe it preferable to have both the initiaof carrier impelling and accordingly to have the discharge of the carrier from the delivery end of the tube cause the cessation of the air flow rather than the operation of a timing device.

The primary object of this invention is to provide an improved power control apparatus comprising means actuable automatically upon insertion of a carrier into the transmission line at a dispatch terminal to initiate flovv of the air impelling current and also actuable automatically when the last carrier is discharged from the transmission line tlo cut off the air current without appreciable c elay.

A further object of this invention is to provide insuch apparatus having a control valve for regulating the carrier impelling air flow, a look by which the valve .is secured in its normal closed position, which look is rendered inoperative when a carrier is inserted into the transmission line.

Another object of this invention is to provide in such apparatus in addition to the control valve for regulating the carrier impelling air flow an auxiliary valve, which when opened, places the control valve housing in direct communication with the atmosphere, said auxiliary valve being closed when the control. valve is open and vice versa, and, if desired, a reciprocable rod or equivalent means actuated by the closure of either valve to initiate the opening of the other valve.

7 As illustrating this invention one embodiment thereof is disclosed in the accompanying drawings, in which Fig. 1 is a fragmentary elevation illustrating a part of a central station desk of a pneumatic system having the improved power control apparatus'applied thereto; I

. Fig. 2 is an enlarged side elevation of a power control apparatus in which the control valve for the carrier impelling air flow is closed as indicated in dotted lines; and

Fig. 3 is a sectional view of such apparatus, showing such control valve open.

In Fig. 1 of the drawings the numeral indicates a fragmentary portion of the central station desk of a pneumatic dispatch systern comprising transmission tubes such, for example, as the tube 11' which leads from the central station to a remote sending station and then back to the central station desk. Each tube 11 is provided with a delivery terminal 12 and an open-ended dispatch terminal 13. A continuation 14 of the tube 11 connects it to a power control apparatus, indicated generally by the numeral 15, which, in turn is connected by a suction tube 16 to a vacuum drum or header 17 in which low pressure is continually maintained by means of a suitable exhauster, pump, or equivalent apparatus, not shown. The above arrangement in general being old and well known in this art, further details thereof are believed to be unnecessary, the present invention being confined to improvements in the powe control apparatus per se.

Referring to Figs. 2 and 3, the power control apparatus comprises a substantially cylindrical housing 20 directly connected through av port 21 to the upper end of the suction tube 16 and through a port 22 to'th'e continuation 14 of the transmission tube 11. Pivotally mounted upon a shaft 23 supported in suitable hearings in the wall of the housing 20 is a control valve 25 -which,' when closed, as shown in Fig. 2, cuts off the connection through the housing between the tubes'16 and 14 and when open, as'shown in Fig; 3, permits'the free passage of air therebetween. The valve is slightly unbalanced with reference to the shaft 23, the upper portion 26 being somewhat longer than the lower portion 27 and furthermore, a flanged plate 28 is secured to the under surface of the portion 26 near the upper edge of the valve so that the valve normally tends to take the closed position shown in Fig. 2.

The housing 20 is closed at its upper end 7 by a cap 30. .Its lower end, however, is open providing a port 31 which may be closed by an auxiliary valve 32 pivotally supported upon a hinge 33 carried by the wall of the housing. A bracket 34 supported by. the tube 14 carries a set screw 35 against which the valve 32rests when open. By adjusting the set screw 35 the length of the opening movement of the valve may be controlled. The valve when open affords direct communication from the interior of the housing 20 to the atmosphere through the port 31.

Mounted on a bracket carried by the valve 32 is a trip bar 41 pivotally connected at its lower end to the bracket 40 and guided at its upper end by a slot formed in a plate 42. The bar 41 obviously will be caused to reciprocate vertically upon the opening and closing of the valve 32 and a counterweight 43 carried by the bar 41 is provided to supplement the action of the force of gravity in causing the bar to descend and the valve 32 to open.

Brackets 45 support a latch bar 46 pivotally mounted intermediate its length upon a pin 47. Fixed on the under face of the portion 27 of'the valve 25 is a boss 48, and the latch bar 46 is so positioned that its upper end 49 will engage the boss 48 under certain conditions and lock the control valve 25 intheclosed position. The lower end of the latch bar 46 is enlarged and consequently is heavier than the upper end so that it tends at all times to descend and rest against the upper face of the valve 32.

Fixed upon the shaft 23 of the valve 25 is an arm 50 upon the ends of which are mounted adjustable balance weights 51, 52 by which the opening tendency of the valve is controlled, the weight 52 being at the right of the center line of the shaft 23 when the valve is closed. A stop comprising a set screw 53 mounted in a sleeve 54 on the housing wall engages the weight 51 and limits the opening movement of the valve.

Minimum flow is provided in any suitable manner as by means of tubes and 61 which, as shown in the drawings, are at right angles to each other and thus form a duct by which the valve 25 is by-passed, the passage of air through the tube 61 being regulated by an adjustable plug 62.

The operation of this device will now be described with respect to the travel of a single carrier through the tube 11, either toward or from the central station. The position of the elements when no carrier is in transit through the tube is illustrated in Fig. 2, the control valve 25 being closed and the auxiliary valve 32 being open. Air is supplied to the housing 20 through the transmission tube 11 and its continuation 14 and also through the port 31 and is drawn therefrom by the exhauster through the minimum flow duct.

Then a carrier is inserted in the transmission tube 11 the supply of air to' the hous ing 20 through the tube is substantially reduced and as a result suction is exerted upon the valve 32, pulling that valve closed. The closing movement of the valve 32 performs two operations first, the latch bar 46 is shifted out of contact with the boss 48 so that the control valve 25 is free to move; second, the post 41 is raised into contact with the flanged plate 28 thus positively initiating the opening movement of the control valve 25. The valve, as soon as it has left its normal closed position, swings under the action of the weights 51 and 52, into the open position shown in Fig. 3 so that the tubes 14 and 16 are directly connected through the housing and as a result a carrier impelling flow is set up in the transmission tube by which thecarrier is moved to its destination.

Upon the discharge of the carrier from the tube a rush of air through the tube to the housing is set up which impacts upon the lower end 27 of the control valve and causes it'to swing from the open posit-ion of Fig. 3 into the closed position of Fig. 2.. As the valve assumes that position the flanged plate 23 contacts with the upper end of the post 41 and forces the valve 32 open if it has not already opened under the force of gravity.

It will be noted that when the valve 32 is closed the latch bar 46 is in such position that the control valve 25 can move freely into its closed position without interference from the upper end 49 of the bar but when the valve 32 is open the lower end of the latch bar swings downwardly and the upper end 49 rises in front of the boss 48, thus holding the valve in its normal closed position, which it retains until a second carrier is inserted into the tube and the above cycle of operations is repeated.

As pointed out above my invention comprises a power control apparatus having a control valve normally closed, an. auxiliary valve by which the control valve housing is di rectly connected to the atmosphere, a latch bar by which the control valve is locked closedand a trip bar by which the opening movement of the control valve is initiated and under some conditions the opening movement of the auxiliary valve is also initiated. While these features are all set forth in the selected embodiment of the invention it will be understood that I am not limited thereto and that other embodiments may be made without departing from the spirit and scope of the inventionas set forth in the following claims.

I claim: I V

-1. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is'closed, said housing having a port through which it is normally in direct communication with the atmosphere and through which air is drawn into the system when the transmission tube is empty and an auxiliary Valve by which said port is closed when a carrier is in the tube.

2. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connectedthereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere and an auxiliary valve by which said port is closed when a carrier is in the tube, the closure of said port initiating the opening movement of the control valve.

3. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said .portis closed when a carrier is in the tube, and

means actuated by the auxiliary valve upon its closure to initiate the opening of the control "alve.

'4. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an 'exhauster connected thereto through a minimum flow of air is permitted when the a control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, the closure of the auxiliary valve being caused by the presence 7 of a carrierin the tube and means actuated thereby to initiate the opening of the control valve. i a i 5. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housingby which the carrier impelling air fiow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is'closed, said housing having a port through which it is normally in direct communication with the atmosphere and through which air is drawninto the system when the transmission tubeisempty and an auxiliary valve by which said port is closed when a carrier is in the tube, said port being opened by the auxiliary valve upon the closure of the control valve by therush of air through the tube incident to the discharge of a carrier therefrom. V

'6. Power control apparatus for a pneumatic'dispatch system of the vacuum minimumflow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster,a control valve in the housingby which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted where the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere and through which air is drawn into the system when the transmission tube is empty, an auxiliary valve by which said port is closed when a carrier is in the tube, and a trip bar carried by the auxiliary valve, which bar is contacted by the control valve upon its closure to initiate the port opening movement of the auxiliary valv V 7. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprisinga housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, and means by which the control valve is locked in the closed position, said means being inoperative when the auxiliary valve is closed. v

8. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow isregulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, and means by which the control valve is locked in the closed position, said means being at all times in contact with the auxiliary valve and rendered inoperative when the latter valve is closed.

9. Power control apparatus for a pneumatic dispatch system of the vacuum minimum fiow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flowis regulated, said valve being closed when the transmission tube is empty and open which a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through'which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, and means by which the control valve is locked in the closed position, said means being rendered inoperative by the auxiliary valve upon its closure.

10. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube,meansby which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary I valve by which said port is closed when a carrier is in the tube, and means by which the control valve is locked in the closed position, said means being contacted by and rendered inoperative by the auxiliary valve upon its closure.

11. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhausterconnected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed when i the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, and a latch bar for holding the control valve in the closed position, the auxiliary valve by its closure render- 7 ing the bar inoperative and initiating the opening of the control valve.

12. Power control apparatus for a pneumatic dispatch system of the vacuum minimum fiow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the urge of said exhauster, a control valve in the housing by which the carrier impelling air 7 flow is regulated, said valve being closed when the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted when the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, a latch for holding the control valve in the closed position and v Vmeans for lifting the control valve from its seat and initiating the opening thereof, the auxiliary valve by its closure rendering said latch inoperative and actuating said lifting means.

13. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube and an exhauster connected thereto through said apparatus, said apparatus comprising a housing through which air flows under the 1 urge of said exhauster, a control valve in the housing by which the carrier impelling air flow is regulated, said valve being closed When the transmission tube is empty and open when a carrier is in the tube, means by which a minimum flow of air is permitted When the control valve is closed, said housing having a port through which it is normally in direct communication with the atmosphere, an auxiliary valve by which said port is closed when a carrier is in the tube, a latch in said housing normally in position for holding the control valve in the closed position, which latch is in an inoperative position When the auxiliary 1 valve opens the port upon the discharge of a carrier from the tube and thereby allows the latch to resume its normal operative position and hold open the control valve uponits opening by the rush of air through the tube incident to such carrier discharge.

Signed by me at Boston, Massachusetts, this 4th day of August, 1930.

FRED R. TAJSEY. 

